You can only change your neighbor's fence with their permission. A neighbor's fence is their property, and altering it without their consent could constitute trespassing or property damage, which may have legal consequences. If you have concerns or disagreements about your neighbor's fence, communicate with them openly and try to reach a mutually agreeable solution. If you believe the fence violates local zoning laws or property regulations, consult with local authorities or seek legal advice to address the issue through proper channels. 

The average lifespan of a wood fence is 15 to 20 years, but some can last for 40 years or more depending on several factors. The type of wood is crucial; for example, untreated pine may only last 5 to 10 years, while pressure-treated pine can last up to 20 years, and cedar's natural resistance can extend its life to 40 years. Other factors include local weather conditions, with wet and windy climates causing faster deterioration, and the quality of maintenance. Higher-end wood, metal posts, and privacy fence styles also tend to last longer.

The maximum recommended slope on which you can build a racked or stepped fence is 45 degrees. After that, construction becomes quite tricky and may require the use of retaining walls or terraces to make the fenced area flatter.

The first step in choosing a reputable dog fencing company is to confirm that the professional has experience in your particular area and maintains positive reviews online. You should also check the Better Business Bureau’s (BBB) website to see if they have accrued customer complaints in the past. Additionally, you can ask the following questions to qualify the pro:

• Do you have experience installing the specific fence material I want?

• Will you pull permits for the installation?

• Will you help get a survey done to make sure I build on my property?

• Do you have a list of referrals?